1. Field of the Invention
The present invention relates to an adjusting strap structure, and more particularly to an adjusting strap structure for a pair of swim fins.
2. Description of the Related Art
The closest prior art of which the applicant is aware is disclosed in U.S. Pat. No. 5,899,781 to McLaughlin, filed on Nov. 7, 1997, entitled by "SWIM FIN INCORPORATING PRONATION COMPENSATION STRUCTURE".
In the McLaughlin prior art, it disclosed a pair of swim fins each comprising a blade 3, a foot pocket 19, a heel strap 45 including two half heel straps 49 each having one distal end secured to the outside of the bottom portion 17 of the foot pocket 19 and the other distal end 53 arranged to come into overlapping contact with the other half heel strap 49 of the pair, and a coupling device 55 for connecting the half heel straps 49 together in temporary connection. The coupling device 55 includes a strip 57 fastened to the distal end 53 of one heel strap 49 and having a plurality of loop elements 61, a strip 63 fastened to the distal end 53 of the other heel strap 49 and having a plurality of hook elements 65 detachably engaged with the loop elements 61 for connecting the two half heel straps 49 together.
However, each of the two half heel straps 49 is fixed to the foot pocket 19 so that the length of the heel strap 45 relative to the foot pocket 19 cannot be arbitrarily varied. Accordingly, it is not easy to adjust the tension and relaxation of the heel strap 45 relative to the user's feet so that the heel strap 45 cannot fit users of different statures, thereby greatly limiting the versatility of the heel strap 45. In addition, the two half heel straps 49 of the heel strap 45 are directly in contact with the user's heel when the user wears the heel strap 45, thereby easily injuring the user's heel after long-term use due to frequent contact and scrubbing action.